Photographic printing apparatus and method for endless sound films



May 21, 1935. v J. A. MAURER, JR

PHOTOGRAPHIC PRINTING APPARATUS AND METHOD FOR ENDLESS SOUND FILMS Filed Feb. 19, 1932 INVENTOR JOHN A.MAU ER JR.

BY MW ATTORNEY Patented May 21, 1935 PATENT OFFICE PHOTOGRAPH! PBINTIN G APPARATUS AND FILMS METHOD FOR ENDLESS SOUND John A. Maurer, Jr., New York, N. Y., assignor to ladle Corporation 0! America, a corporation of Delaware Application February 19, 1932, Serial No. 593,97.

5 Claims. (CI. -75) practicable as a commercial proposition as well as unreliable from the standpoint of uniformity.

One object of the present invention is to provide a method of printing such films.

Another object of the invention is to provide an apparatus for printing such films.

Another object of the invention is to provide a method of printing such films in the form of an unbroken series.

Another object of the invention is to provide an apparatus for printing such films in the form of an unbroken series.

Another object of the invention is to provide a method and apparatus for printing such films upon an unbroken strip of sensitized emulsion so that it may be developed, etc., in any manner ordinarily used commercially in the handling of analogous films.

Another object of the invention is to provide a method of and apparatus for producing such films in commercial quantities at a cost commensurate with that of the more usual types of sound records.

In the drawing:

Fig. 1 is a diagrammatic illustration of one form of the method and apparatus.

Fig. 2 is a diagrammatic illustration of a second form of the method and apparatus.

Fig. 3 is an illustration of the negative film as prepared for performance of the method or use in the apparatus, and

Fig. 4 is an illustration of a sequence of steps in the performance of the method.

Referring first to Fig. 1, I represents a roll of positive raw stock from which film is drawn by friction rollers 2 through the printing gate 3. A loop of negative film 4 passes through the film gate 3 in contact with the positive stock and this loop 4 carries a sound-track or a multiplicity of sound-tracks, and carries also a mark 9, the printed impression of which on the positive shows where it should be cut'to separate the adjacent complete impressions of the negative. This mark 9 may consist of an inserted piece of blank film shown in Fig. 3or may consist of a line ruled across the film as shownin Fig. 1. or if it is desired to have this portion of the positive prints appear clear and of appreciable length, it may consist of a portion of opaque film.

Exposure is accomplished by the lamp 6 and the quantity of exposure may be determined by either varying the separation of the portions of the film gate 3 or by changing the speed at which the film travels, or by changing the intensity of the light.

The films are held in lateral alignment at the gate by means of the idlers 8, and the remainder of the loop 4 is supported on idlers I or in any other convenient manner which will permit it to be continuously and regularly fed through the gate.

Details of construction of the printing machine are not shown as they may be made in any manner convenient or customary in the art, and such details of course would include such things as means for driving the take-up reel and the feed rollers 2, a lamphouse for the lamp 6, and possibly a condenser system therefor, etc.

Particular points of novelty in the arrangement shown include the employment of the negative in the form of a continuous loop which moves continuously at a uniform speed past the printing aperture and the feeding of this loop and the positive film stock by frictional contact with one or more rollers which maintain them in intimate engagement with each other.

It will be apparent that this printed roll positive stock which may have a length of a thousand feet or more can be developed by any continuous processing machine well known in the art, and it will then be ready for the performance of the remaining steps of the method as will be described after the description of the printed apparatus and method shown in Fig. 2.

In Fig. 2, film from the roll of raw stock i is drawn across a printing table Ill and is taken up upon the reel 5. The feed of this film across the table may be accomplished in any convenient manner such that a predetermined amount of the raw stock can be fed across the table at one time. The simplest manner of accomplishing this, of course, would be to make an index mark at the lefthand end of the printing table and then after the printing operation to merely wind up the film on the take-up reel until the index mark had passed onto the right of the table, then repeat the printing operation, etc.; but the film may be fed by any other equivalent arrangement such,

for example, as a friction roller which performs a predetermined number of revolutions at each operation thereof, or by a drive mechanism on a take-up reel 5 which compensates for the increase in diameter of the rolling film thereon.

In this case the negative is produced in the form of a straight strip H which is maintained in fixed relation to the printing table and pressed firmly against the raw stock by some appropriate means as the sheet of plateglass l2. Masks l6 are provided to limit the exposure to the length of the film slightly greater than the negative length.

The negative may rest against the raw film stock with such slight pressure that the film stock can be moved without lifting the negative, but this is rather unsatisfactory in that it is sure to produce scratches upon both the positive and the negative films. A much more satisfactory method is to raise the plateglass and negative film slightly during the time the raw stock is being fed across the printing table and then during the 1 printing operation to press the negative firmly against the raw stock by means of the plateglass.

The illuminating means provided is preferably, as shown, in a straight tubular type of mercury vapor lamp extending the full length of the negative strip, although it is obvious that other types of lamps may be used if desired.

The shutter I5 is provided for the purpose of determining the length of the exposure, this shutter being removed from the path of the light during exposure and replaced in the light path at the conclusion of the exposure and during the movement of the raw stock across the film table. The movement of the shutter l5 may. of course, be accomplished by any appropriate means either electrical or mechanical, or it may even be removed manually.

It will be apparent that, although the operation of the apparatus shown in Fig. 2 is intermittent instead of continuous, it produces the same ultimate result as the apparatus shown in Fig. 1; that is, a long strip of exposed positive stock having a series of latent impressions produced from the sound record negative; and this strip of positive stock is, as explained above, capable of development etc. in the usual apparatus.

The remainder of the process is illustrated diagrammatically in Fig. 4. As shown here, the sound record prints are separated at the indications produced by the insert 9 in the negative film. The ends of the section of the positive film are then trimmed very accurately to length and cemented together to form a continuous loop similar to the original negative. It is, of course, highly desirable that the ends of the film should be trimmed accurately and that the splice should be such as will not produce any click in the sound reproducer each time the splice passes the photocell. For this reason it is desirable to use a butt splice on this type of film as distinguished from the lap splice used in ordinary motion picture films. I have devised an apparatus aooaisi for making such a splice readily and accurately but, inasmuch as it is obviously possible for such 9. splice to be made by hand, the said apparatus is not material to the disclosure of the present application and is mentioned merely to show that there is no commercial difficulty involved in this feature of the present invention. 5

The completed loop of positive film looks, of course, like the last form shown under Fig. 4 and may contain a helical sound-track of comparatively slight width and in the form of a helix of several hundred turns so that a comparatively short loop of film is capable of playing for an hour or more and, at the same time, is produced at a cost within a few cents since the cost per foot is approximately the same as that of commercial motion picture positive prints.

I claim:

1. The method of making sound'records in the form of an endless loop having a helical sound-track for film phonographs comprising printing a. multiplicity of sequential positives upon a considerable length of film stock, developing the images, separating the individual prints and then joining the two ends of each print by a butt splice.

2. The method of making sound records in the form of an endless loop having a helical soundtrack for film phonographs comprising printing a multiplicity of sequential positives upon a considerable length of film stock, developing the images, separating the individual prints and then joining the two ends of each print by a butt splice whereby the splice will be inaudible on reproduction of the sound record.

3. The method of making sound records in the form of an endless loop having a helical sound-track for film phonographs comprising printing a multiplicity of sequential positives upon a considerable length of film stock with an index mark between each print and the next, developing the images, separating the individual prints and then joining the two ends of each print.

4. The method of making sound records in the form of an endless loop having a helical sound-track for film phonographs comprising printing a multiplicity of sequential positives upon a considerable length of film stock with an index mark between each print and the next,

developing the images, separating the individual prints at said index marks and then joining the two ends of each print. I

5. The method of making sound records in the form of an endless loop having a helical soundtrack for film phonographs comprising printing a multiplicity of sequential positives upon a considerable length of film stock with an index mark between each print and the next, developing the images, separating the individual prints at said index marks and then joining the two ends of each print by a butt splice.

JOHN A. JR. 

